Extracting carbon dioxide from ambient air would make it possible to use carbon based fuels and deal with the greenhouse gas emissions after the fact. Since CO2 is neither poisonous nor harmful in parts per million quantities but creates environmental problems simply by accumulating in the atmosphere, it is possible to remove carbon dioxide from air in order to compensate for an equally sized emission elsewhere and at different times. The overall scheme of air capture has been described elsewhere.
The production of carbon dioxide (CO2) occurs in a variety of industrial applications, such as the generation of electricity by burning coal in power plants. Flue gas from coal-burning power plants typically contains a high percentage of nitrogen, about 13% CO2, about 3% oxygen, about 10% water and less than 1% of various pollutants. To sequester CO2 during the operation of coal burners in power plants, CO2 must be separated from the flue gas, which is hot, e.g., temperatures from about 200° C. to about 1000° C. depending on its specific locations in the flue gas lines of the coal-burning power plant. In a carbon constrained world, central sources of CO2 like power plants are likely to capture their own CO2 from the power plant stack.
Hydrocarbons are typically the main components of fuels that are combusted in combustion devices, such as engines. Exhaust gas discharged from such combustion devices contains carbon dioxide gas, which at present is simply released to the atmosphere. However, as greenhouse gas concerns mount, carbon dioxide emissions from all sources will have to be curtailed.
Scrubber designs for separating CO2 from air already exist, but they are limited to packed bed type implementations whose goal is typically to remove all traces of an impurity from another gas. The disadvantages in the art are addressed and overcome by the carbon dioxide separation membranes and methods of use thereof as embraced by the present invention.